For a team that would like to keep a young quartet of sure-to-be-expensive players, last week's news of a steadily fattening NFL salary cap was particularly welcome for the 49ers.

How can they possibly pay quarterback Colin Kaepernick, outside linebacker Aldon Smith, guard Mike Iupati and wide receiver Michael Crabtree, all of whom are entering the final year of their rookie contracts? That question became a bit less vexing when it was revealed the salary cap, which was $123 million in 2013, will balloon to $133 million in 2014 and could rise to at least $150 million by 2016.

In the short term, however, the extra $10 million available to teams this season could work against the 49ers. With free agency beginning at 1 p.m. Tuesday, the 49ers, who are averse to engaging in bidding wars for their on-the-market players, could find it harder to retain the trio probably at the top of their priority list: safety Donte Whitner, cornerback Tarell Brown and placekicker Phil Dawson.

Former NFL personnel executive Bill Polian, now an ESPN analyst, expects the market for such players to be a bit more robust this year.

"History tells you that there will be more deals out there for big money than there were last year," Polian said. "I think the biggest impact may come - and I underline the word may - with the so-called middle class. Last year, a lot of those fellas got one- and two-year deals."

The so-called "legal-tampering period" of free agency begins at 9 a.m. Saturday, allowing agents to start negotiations before contracts can be signed Tuesday.

Whitner, who will turn 29 in July, and Brown, 29, are expected to test the market. Given their ages, it will probably be their last opportunity to land a lucrative, multiyear deal.

Whitner, selected to his first Pro Bowl berth in 2012, will earn a raise after signing a three-year, $11.75 million contract in 2011. Meanwhile, Brown, who unwittingly forfeited $2 million in base salary in a contract snafu last year, also figures to cash in: Polian ranks Brown among the top three free-agent cornerbacks.

In December, general manager Trent Baalke said the team had started contract discussions with Dawson and wide receiver Anquan Boldin. Boldin signed a two-year deal Monday, but the kicker remains unsigned after he outperformed his $2.25 million base salary in 2013.

If recent history is a guide, the 49ers won't overpay to keep Whitner, Brown or Dawson.

Instead, they could eventually use some of their extra salary-cap cash to ensure part of their quartet - Kaepernick, Smith, Iupati and Crabtree - never become free agents. As Polian noted, the top players never reach the open market.

"The best players are signed," he said. "So (free agents), essentially, are B players whose agents are looking for A money."

Dobbs deal: Niners backup defensive tackle Demarcus Dobbs, 26, a restricted free agent, will be tendered a non-guaranteed, one-year contract by the 49ers at the lowest level, $1.431 million, USA Today reported. Dobbs will still be able to receive offers from other teams when free agency begins Tuesday, but the 49ers can match any offer. The 49ers would not be compensated with a draft pick if Dobbs signs elsewhere because he was an undrafted free agent.